1. Field of the Invention
The present invention relates to a crimp terminal adapted to be crimped onto an end of an electric wire provided for an automobile or the like, and a method of manufacturing a terminal-provided wire including the crimp terminal.
2. Description of the Related Art
Conventionally crimping is often used to attach a terminal to an end of an insulated cable. The crimping is performed by caulking a conductor barrel formed in advance on the terminal to the end of a conductor of the insulated cable using a die (described in Patent Document 1, for example).
FIGS. 11 and 12 show a structure of a terminal-provided wire having a conventionally typical crimp terminal. The terminal-provided wire has an electric wire 20 and a crimp terminal 10 crimped onto an end of the electric wire 20.
The wire 20 is made of a conductor 22 and an insulation cover 24 covering the conductor 22 radially, the insulation cover 24 partially emitted at the end of the electric wire 20 to expose the conductor 22.
The crimp terminal 10 has an electrical connection portion 12 and a crimped portion in front and rear. The electrical connection portion 12 is a female type shaped in a box into which a not shown male type terminal can be fitted. The crimped portion includes a bottom wall 14 which is a basal portion reward in an axial direction from the electrical connection portion 12, a pair of right and left conductor barrels 16 each extending perpendicular to the axial direction from the bottom wall 14, and a pair of right and left barrels 18 each extending parallel to the conductor barrels 16. Both of the conductor barrels 16 and the insulation barrels 18 are approximately U-shaped in an axial view before bending.
For crimp of the crimp terminal 10, the end of the electric wire 20 is set onto the bottom wall 14 and, in this state, each of the conductor barrels 16 and each of the insulation barrels 18 are inwardly bent by pressing with dyes. Both of the conductor barrels 16 are thereby crimped onto the conductor 22 exposed at the end of the electric wire 20 so as to embrace the conductor 22. In the same manner, both of insulation barrels 18 are so crimped onto the insulation cover 24 at a position adjacent to the conductor 22 as to embrace the insulation cover 24 from both sides thereof.
To ensure a favorable electrical connection in this terminal-provided wire, there is required an evaluation of the quality of the crimp of the conductor barrels 16 onto the conductor 22 in an inspection on the electric wire; however, the crimp state, especially the crimp level of the conductor barrels 16 onto the conductor 22 (that is, a biting depth) cannot be easily evaluated based on its appearance. In addition, a radial reduction in the electric wire 20 and a size reduction in the crimp terminal 10 make the evaluation more difficult.
The Patent Document 1 discloses indication grooves formed in an outer surface of conductor barrels corresponding to a serration formed in an inner surface of the conductor barrels, the barrels calibrated between the grooves; however, the grooves and the calibration cannot indicate a crimp level of the conductor barrels. The grooves etc., formed in shapes extending perpendicular to the terminal axial direction (that is, longitudinally of the conductor barrel), cannot teach the crimp level of the conductor barrels onto the conductor (that is, a biting depth).
Patent Document 1: Japanese Patent Application Publication No. 2001-357901